DIFFERENTIAL EXPRESSION OF IMMUNOGENIC PROTEINS ON MYCOBACTERIUM TUBERCULOSIS CLINICAL ISOLATES FROM BUENOS AIRES, ARGENTINA.

LAURA KLEPP; PABLO SCHIERLOH; CAMILA VAZQUEZ; ROXANA VALERIA ROCHA; FEDERICO BLANCO; MARINA GARCÍA; BEATRIZ LÓPEZ; VIVIANA RITACCO; MARÍA DEL CARMEN SASIAIN; FABIANA BIGI

CANELA, Brasil

Congreso; VII MEETING SLAMTB; 2014

Sociedad Latinoamericana de tuberculosis y otras micobacteriosis

Background and Objectives: Molecular epidemiology has revealed that Mycobacterium tuberculosis (Mtb), formerly regarded as highly conserved specie, displays a considerable degree of genetic variability that can influence the outcome of the disease as well as the innate and adaptive immune response. Recent studies have demonstrated that Mtb families found worldwide today differ in pathology, transmissibility, virulence and development of immune response. Methods: By proteomic approaches we search for proteins that were differentially expressed between a local clinical isolate from Latin-American-Mediterranean (LAM) and from Haarlem (H) lineages. In order to analyze the immunogenic ability of differentially expressed proteins, we cloned and produced recombinat fusion proteins and tested specific antibody responses in TB patients será by ELISA and FACS. Results: We identified seven differentially expressed proteins that were confirmed at transcriptional level. Four of these proteins were succesfully cloned: Rv2241, Rv0009, Rv0407 and Rv2624c. We found that these proteins induced humoral immune responses in patients with drug-sensitive and drug-resistant tuberculosis with substantial cross-reactivity among the four proteins. Moreover, such reactivity was also correlated with anti-Mtb-cell surface IgM, but not with anti-ManLAM, anti-PPD or anti-Mtb-surface IgG antibodies. Conclusion: By combining classical immunochemical assays with proteomics approaches we identified four previously undescribed Mtb antigens that were differentially expressed in clinical isolates that circulate currently in our population.